玉米须黄酮类成分提取工艺及抗氧化活性物质基础研究

Studies on Extraction Technology and Antioxidant Activities Basis of Flavonoids from Zea Mays L.

关键词:  玉米须  黄酮  响应曲面  抗氧化活性  构效关系

Key words:  Zea mays L.  flavonoids  response surface methodology  antioxidant activities  structure-activity relationship

摘要:

目的 优化玉米须总黄酮的提取工艺，鉴定抗氧化活性馏分中的化学成分，并进行构效关系探讨。方法 采用响应曲面法优化总黄酮提取工艺，测定不同提取物的DPPH，ABTS及FRAP总抗氧化活性，并进行相关性分析。采用D101大孔树脂柱对提取物进行分离，采用LC-MS对活性馏分中的成分进行鉴定。测试黄酮单体化合物的抗氧化活性。结果 黄酮提取的最佳条件为乙醇体积分数65%，提取时间78 min，提取温度86℃，总黄酮提取量为2.35 mg·g^-1。利用大孔树脂分离后，黄酮类成分主要聚集在60%乙醇-水洗脱馏分。总黄酮含量与抗氧化活性间存在着显著的正相关性。此外，从活性馏分中鉴定了7个黄酮类成分。对其中6个化合物的活性进行了测试，并进行了构效关系探讨。结论 响应曲面法能有效地优化玉米须总黄酮提取工艺。玉米须的抗氧化活性成分主要为黄酮类化合物。

Abstract:

OBJECTIVE To optimize conditions for the extraction of total flavonoids from Zea mays L.. To identify the structures of compounds from active fraction and to discuss the structure-activity relationship between flavonoids and antioxidant activities. METHODS Response surface methodology was used to optimize conditions for the extraction of total flavonoids from Z. mays. DPPH, ABTS and FRAP methods were used to test the antioxidant activities of different extracts. The relativities of the data were analyzed. D101 macroporous resin column was applied to isolate the extract. LC-MS was used to identify the compounds from the active fraction. The antioxidant activities of the flavonoids were tested. RESULTS The best extraction conditions were as follows:ethanol concentration was 65%, extraction time was 78 min and extraction temperature was 86℃. The content of total flavonoids could reach 2.35 mg·g^-1. It indicated that 60% ethanol fraction had the most content of total flavonoids after eluted from macroporous resin column. There was a significant positive correlation between total flavonoids content and antioxidant activity. What's more, seven flavonoids were identified from the active fraction. The antioxidant activity of six flavonoids were tested. The structure-activity relationship was discussed. CONCLUSION Response surface method is effective to optimize the extraction of total flavonoids from Z. mays. Flavonoids are the main antioxidant ingredients of Z. mays.